1. Field of the Invention
The present invention relates to an etching method.
2. Description of the Related Art
Etching methods for etching a silicon oxide film using an etching gas including CH2F2 gas at low temperatures are known (e.g., see Japanese Unexamined Patent Publication No. 2015-159308). Japanese Unexamined Patent Publication No. 2015-159308 describes an etching gas for forming a contact hole pattern having a high aspect ratio.
Also, an etching method is known that involves exciting a gas containing hydrogen gas, hydrogen bromide gas, nitrogen trifluoride gas, and at least one of hydrocarbon gas, fluorocarbon gas, and hydrofluorocarbon gas, and etching a multilayer film in the layering direction from its surface down to a midpoint position to forma hole in the multilayer film (e.g., see Japanese Unexamined Patent Publication No. 2015-153941).
However, the above-described techniques do not address controlling where reaction products generated during plasma etching are to be deposited on a mask film through selection of the appropriate combination of gases. Thus, according to the above-described techniques, it is difficult to the control the position where reaction products are to be deposited on the mask film by controlling a gas to be added to the etching gas.